Riallo 40 F5 burner question

[PHPaul]

I had a Buderus G115WS/4 hot water boiler installed by a professional. It has a Riallo 40-F5 burner on it. At the same time the furnace was installed, a 5" stainless steel chimney liner was installed.

I use a wood stove for supplemental heat, so it's not uncommon for the furnace not to come on at all during the day.

The problem is that when it DOES come on (usually in the early evening when outside temperature starts going down) it is EXTREMELY noisy. The damper slams back an forth (once violently enough to dislodge the flap from it's pivots) and there is a roaring noise audible even on the second floor (the furnace is in the basement). I can feel random pulses of exhaust coming out of the damper tee.

Once the furnace cycles a few times, it operates normally. This makes me think that the issue is related to the furnace firebox and/or chimney being cold.

The original installer came back and double checked the adjustments on the burner and said there was evidence of an air leak in the line. He tightened all the fittings. It did not improve the situation.

The next idea was that the pump on the burner was not strong enough to draw fuel through the line. The tank is in the basement on the same level as the furnace, but the line was run up from the tank and across the floor joists over to the furnace and back down so as to avoid running the line on the floor.

I had the line rerouted and sleeved so that the fuel is gravity feed, had the pump bled and all the settings double checked. No change in the symptoms.

The furnace works very well in all other respects and I am VERY pleased with the oil consumption, but this noisy, border-line violent cold start is driving my wife to distraction. We all know that if Momma ain't happy, ain't nobody happy

A fairly comprehensive search has not found any information on this problem but does seem to indicate that Riallo burners are touchy. I'm even considering going to the expense of changing to a different brand of burner.

I'd appreciate ANY input on this issue. I'm not a pro, and I'm not planning any DIY action. The guy that put it in is not being very responsive (but to be fair, he's a one-man show and VERY busy this time of year), and all the service department at my oil dealer will do is adjust it by the book. I'm just looking for some solid information in an attempt to fix this issue.

[Moose]

Is your chimney an exterior masonry (brick or other?) Do you have make-up air for the wood & oil? Sounds like the oil burner is having to warm the chimney before it will run properly, then it's ok. The draft damper (barometric) should be partly open even when the oil isn't operating, & the metal pipe shouldn't be cold. A pre-purge cycle could maybe help.

[PHPaul]

Is your chimney an exterior masonry (brick or other?) Do you have make-up air for the wood & oil? Sounds like the oil burner is having to warm the chimney before it will run properly, then it's ok. The draft damper (barometric) should be partly open even when the oil isn't operating, & the metal pipe shouldn't be cold. A pre-purge cycle could maybe help.

It's a 5" stainless liner inside an old masonry chimney. The chimney is an interior chimney. Wood stove is on a separate chimney. Furnace is in the basement which leaks like a sieve, so I don't think combustion air is an issue.

Draft damper does sit partially open when not running. Metal stack from chimney adapter to furnace is distinctly cold to the touch when the furnace sits all day.

I'm wondering if a draft inducer fan would be a solution.

[snupytcb]

it does sound like the chimney is cold at start. this is not un-common. a good oil tech should be able to lessen the cold start bang with some minor adjustments.